sachem v.3 hi-end monoblock amplifier
Please click here to read the review of a sachem system, made by Dr. Richard Varey on the Witchdoctor hi-fi magazine.
the new sachem v.3 (black version)
The success of the original sachem’s first series persuaded us, many years ago, to continue, leading to the release of sachem v.2 series. And now, the latest series, sachem v.3, has arrived.
The v.3 version features a redesigned PCB with a layout as compact as possible, and minor modifications to the circuitry and components. All is enclosed in a new cabinet of pure and linear design, carved from solid bars of aluminium and machined to perfection. Additionally, the v.3 boasts another significant difference from other hi-end amps: it's wire-free! Another peculiarity is the unusual response on the musical transients: fulminant "speed" and total sound control, which is paramount in an amplifier. I have live recordings of big classical orchestras performing "crazy" modern music, and with this very complex music, the v.3 seems to fully enjoy itself, giving you a feeling of incredible clarity and endless power, on peaks of more than 90dB of dynamic range, at live volume! To give you an idea of its qualities, you could look at the testimonials page on this website. However, to fully discover its superiority and materially realise what we have achieved, we highly recommend that you compare the sachem v.3 to any hi-end amps on the market, without budget constraints and using very dynamic and well-recorded CDs. Unlike other amps, the v.3 loves very complex loads, so make these comparisons employing so-called "difficult" speakers. You'll find that It thrives where others falter!
an overview of the sachem v.3 monoblock and ... a few extra considerations
The text below has been partially copied from the Owner's manual included with every sachem v.3. Additionally, it contains notes that are useful for understanding the "philosophy" behind the amplifier, as well as making you aware of technical and hi-fi related issues that you will never read about in any hi-fi magazine or hear about in a hi-end shop.
sachem v.3 - back panel
We dedicated over a year to electrical and sonic research, completely redesigning and compacting the circuits on the PCB (printed circuit board) while widening and shortening the tracks to minimise their electrical resistance. Throughout this process, we meticulously evaluated various top-quality new components and experimented with subtle modifications to the original circuits. Finally, we arrived at this v.3 version, which "doesn’t sound", or rather, "sounds" as discreetly as possible. Audiophiles often forget that hi-fi equipment should not function as an additional musical instrument with its own distinct sound; rather, they should remain neutral machines!
To achieve this essential goal, we have adopted and developed an interesting circuit, incorporating the most modern, high-performance, top-quality components, in an incredibly clean and wire-free layout.
The greatest advantage of monoblock amplifiers is that they can be positioned close to the speakers, minimising the length of the speaker cables. Consequently, this setup significantly improves the sound quality, dynamics, speed, and control. So, we highly recommend placing each monoblock very close to its speaker, in free air on a small stand, or even on the floor (if not carpet). We believe all high-priced amplifiers should be made in monoblock configuration because the use of long speaker cables, regardless of price, make, or any divine intervention, always significantly degrades the sound.
A speaker is a very complex electrical load (anything but a pure resistor), and the cable adds its electrical parameters (resistance, inductance, and capacitance) to those of the speaker, interacting to further modify the final load seen by the amplifier. Considering that the electrical parameters of a cable are given "per metre", it's intuitive that, by increasing its length, you also increase their values and, consequently, the importance of their effects. Instead, a good quality shielded interconnect (low capacitance, inductance, and resistance), between a preamp with low output impedance and the power amps, does not affect the sound. Even assuming it does, the supposed loss will be significantly less than that of using a long speaker cable.
The sachem v.3 can joyfully drive any type of loudspeaker, irrespective of their load complexity, impedance and efficiency. Indeed, it loves capacitive and inductive loads more than purely resistive ones!
This peculiarity is essential for unlocking the full potential of your speakers. However, it isn’t necessarily present in the "DNA" of every so-called "exclusive" amplifier.
That’s why amplifiers can sound distinct when driving different pairs of speakers.
Now, when it comes to power, some audiophiles believe that a 90W amplifier cannot adequately drive a low-efficiency speaker. However, if the amp is a sachem v.3, they’re mistaken.
We have tested our monoblocks driving a pair of 82dB (1W/1m) speakers at “unusual” volumes with fantastic results: very fast transients (for what’s possible with this kind of "conceptually wrong" speakers), and not a trace of clipping.
No miracles, this is possible because a sachem v.3, if asked, delivers, without strain, current peaks of 20A, resulting in instant musical peaks (on a load of 8Ω) of 3200 W! On the other hand, we believe it is extremely difficult, perhaps impossible, to make a high-powered amplifier (about 200W RMS 8Ω, or more) with such a refined sound. So, we opted for a mid-powered solution, incorporating a "lightning", endless dynamic range, thanks to monstrous current delivery and a very low internal impedance. This parameter plays an essential role in the "liveliness" and "speed" of an amplifier's sound.
If we then reflect a little, with the advent of active subwoofers in domestic settings, for driving the main speakers (correctly rolled off in the bass range, to join the sub), there is no longer the need for very powerful amps, but for very accurate and very fast ones!
So, my advice to the audiophile who looks for sound perfection is to buy a pure v.2, a pair of v.3, a very serious sub, and replace his useless power-hungry “dinosaurs” with better sounding, smaller speakers, which, differently to the "dinosaurs", always have many more chances of delivering coherent and accurate sound in the mid-high range. Indeed, if designed by a good technician, the smaller dimensions of their cabinets, at least, allow the adoption of interesting shapes, with a much smaller front panel, more respectful of the basic rules of physics-acoustics: diffraction, reflection, phase etc.
Please read the first two articles on the school of hi-fi page to learn more about this paramount topic.
sachem v.3 inside. Please note the stunning wireless layout.
technically speaking
A sachem v.3 features a fully complementary design, with a dual differential input stage, followed by a dual complementary differential single-ended voltage gain stage, operating in A-class, at high current. Each monoblock features an oversized 300VA toroidal transformer, that feeds twenty audio-grade, very low impedance and ESR capacitors through a 35A full-wave bridge rectifier. These capacitors provide a total capacitance of 66.000μF and are paralleled with two exceptional WIMA polypropylene caps (MKP10 series). All the resistors feature “metal film” technology, with ±0.1% tolerance and a temperature coefficient of ±15ppm/°C. For the common man, this means veeeery low thermal noise. The power stage is handled by 6 selected and matched Darlington devices, with a collector peak current of 20A each, to achieve low open-loop output impedance and linear high-current capacity. This ensures very smooth output transitions, without any audible crossover or switching distortion, even under high-current output conditions. The whole power supply and the Darlingtons of the power stage are so oversized that the result is a terrific peak max transient current of 20A on the speaker, equivalent to peaks of 1.6 kW @ 4Ω and 3.2 kW @ 8Ω !! The other four current-filtering capacitors inside the circuit feature polypropylene dielectric, while the only one in the signal path (in the feedback circuit) is a bi-polar Nichicon Muse series, top audio-grade, and, in its turn, paralleled with polypropylene capacitors WIMA, MKP10 series. It's a fact that capacitors in the signal path affect the sound negatively and most circuit typologies require many capacitors in this area. We did things differently and, in our knowledge, the sachem v.3 is one of the very few amplifiers, if not the only one, with just one capacitor in the signal path, on the feedback circuit (compulsory in any amp)! Furthermore, and probably this is a feature unique to our amplifier if you set it up for a rolled-off output (for example, when you join a sub to the system, or just to "humanise" the booming in floorstander speakers), this electrolytic capacitor is by-passed and the signal "sees" ONLY polypropylene (high-speed capacitors WIMA MKP10 series)! Having achieved our goal of using only one capacitor on the signal path, we are convinced that we have made an important difference in sound fidelity. The v.3's euphonic sound, the full richness of original unchanged harmonics, the incredible transparency, the silky softness of the mid-high range, the endless and lightning dynamic range, plus the “sculptural” quality and speed of its bass range, all depend to no small degree on this. The carefully considered grounding system on the state-of-the-art PCB eliminates internal loop currents in the ground path and assures a high level of immunity to noise and external interferences. However, to be honest, in sachem v.3 there is a short wire, and it belongs to the probe of the thermometer in the heatsink. It's impossible to avoid this wire, and completely useless as well, considering that the thermometer has nothing in common with the audio electronic circuits. The sachem v.3 is temperature-compensated, and the perfect performance of the amplifier is assured after a quite short warm-up period of less than ten minutes or until the display of the thermometer on the front panel reads 32°C. So, there is NO need at all to leave these units permanently powered up, in respect of the environment, waste of power and their own SAFETY. In this regard, at the end of the listening session, our strong general advice is to turn off not just the monoblocks, but the entire hi-fi system, possibly by a main switch, which, in our view, should be compulsory in any hi-fi system! This precaution safeguards all your system components from natural disasters and possible power surges. Additionally, note that the electrolytic capacitors in the power stage of any element of your system have a finite lifespan, measured in operating hours, so ... draw the obvious conclusions. The thermometer also serves another function: it turns off the amp when the heatsink reaches a temperature of 75°C and turns it back on after cooling to 50°C. For normal use, even at a very high volume, it's more than unlikely to reach the top temperature! The sachem v.3 is a completely reliable amplifier. Every unit is deeply tested for 3 hours at full power into a 4Ω load (1V input, 1kHz) and for 12 hours at half power, into a 4Ω load, with "pink noise".Regarding its reliability, the first sachem went on the market in early 2003, and we haven't had any serious failures reported so far, apart from the replacement of four main power switches in the first series, and one monoblock with the final stage destroyed by a short circuit on the speaker cable, made by the owner (my best friend, ha, ha!). Furthermore, when on stage, the Sachem Guitar combo seems to enjoy "shooting out" more than two hours of killer sound without any strain, which speaks for itself! You surely know that this kind of performance is neither advisable nor achievable with so-called hi-end amplifiers!
A sachem v.3 features a fully complementary design, with a dual differential input stage, followed by a dual complementary differential single-ended voltage gain stage, operating in A-class, at high current. Each monoblock features an oversized 300VA toroidal transformer, that feeds twenty audio-grade, very low impedance and ESR capacitors through a 35A full-wave bridge rectifier. These capacitors provide a total capacitance of 66.000μF and are paralleled with two exceptional WIMA polypropylene caps (MKP10 series). All the resistors feature “metal film” technology, with ±0.1% tolerance and a temperature coefficient of ±15ppm/°C. For the common man, this means veeeery low thermal noise. The power stage is handled by 6 selected and matched Darlington devices, with a collector peak current of 20A each, to achieve low open-loop output impedance and linear high-current capacity. This ensures very smooth output transitions, without any audible crossover or switching distortion, even under high-current output conditions. The whole power supply and the Darlingtons of the power stage are so oversized that the result is a terrific peak max transient current of 20A on the speaker, equivalent to peaks of 1.6 kW @ 4Ω and 3.2 kW @ 8Ω !! The other four current-filtering capacitors inside the circuit feature polypropylene dielectric, while the only one in the signal path (in the feedback circuit) is a bi-polar Nichicon Muse series, top audio-grade, and, in its turn, paralleled with polypropylene capacitors WIMA, MKP10 series. It's a fact that capacitors in the signal path affect the sound negatively and most circuit typologies require many capacitors in this area. We did things differently and, in our knowledge, the sachem v.3 is one of the very few amplifiers, if not the only one, with just one capacitor in the signal path, on the feedback circuit (compulsory in any amp)! Furthermore, and probably this is a feature unique to our amplifier if you set it up for a rolled-off output (for example, when you join a sub to the system, or just to "humanise" the booming in floorstander speakers), this electrolytic capacitor is by-passed and the signal "sees" ONLY polypropylene (high-speed capacitors WIMA MKP10 series)! Having achieved our goal of using only one capacitor on the signal path, we are convinced that we have made an important difference in sound fidelity. The v.3's euphonic sound, the full richness of original unchanged harmonics, the incredible transparency, the silky softness of the mid-high range, the endless and lightning dynamic range, plus the “sculptural” quality and speed of its bass range, all depend to no small degree on this. The carefully considered grounding system on the state-of-the-art PCB eliminates internal loop currents in the ground path and assures a high level of immunity to noise and external interferences. However, to be honest, in sachem v.3 there is a short wire, and it belongs to the probe of the thermometer in the heatsink. It's impossible to avoid this wire, and completely useless as well, considering that the thermometer has nothing in common with the audio electronic circuits. The sachem v.3 is temperature-compensated, and the perfect performance of the amplifier is assured after a quite short warm-up period of less than ten minutes or until the display of the thermometer on the front panel reads 32°C. So, there is NO need at all to leave these units permanently powered up, in respect of the environment, waste of power and their own SAFETY. In this regard, at the end of the listening session, our strong general advice is to turn off not just the monoblocks, but the entire hi-fi system, possibly by a main switch, which, in our view, should be compulsory in any hi-fi system! This precaution safeguards all your system components from natural disasters and possible power surges. Additionally, note that the electrolytic capacitors in the power stage of any element of your system have a finite lifespan, measured in operating hours, so ... draw the obvious conclusions. The thermometer also serves another function: it turns off the amp when the heatsink reaches a temperature of 75°C and turns it back on after cooling to 50°C. For normal use, even at a very high volume, it's more than unlikely to reach the top temperature! The sachem v.3 is a completely reliable amplifier. Every unit is deeply tested for 3 hours at full power into a 4Ω load (1V input, 1kHz) and for 12 hours at half power, into a 4Ω load, with "pink noise".Regarding its reliability, the first sachem went on the market in early 2003, and we haven't had any serious failures reported so far, apart from the replacement of four main power switches in the first series, and one monoblock with the final stage destroyed by a short circuit on the speaker cable, made by the owner (my best friend, ha, ha!). Furthermore, when on stage, the Sachem Guitar combo seems to enjoy "shooting out" more than two hours of killer sound without any strain, which speaks for itself! You surely know that this kind of performance is neither advisable nor achievable with so-called hi-end amplifiers!
sachem v.3 (silver version)
connections and Installation
On the back panel of each monoblock, there are the connection sockets: the red input RCA socket receives the signal from your preamp. The white one is a line output that can be used for feeding the signal to other units, in multi-amplification, or for driving an active subwoofer if you don't want to connect it to the preamp. At this point, I have to introduce you to an uncommon but very useful facility of our amplifier: the ability to select a flat response or, via its passive high-pass filter, a 6dB/oct rolled-off response, with three selectable -3dB points at different frequencies. You must choose one of these roll-off options if you connect a subwoofer (contact us for further explanation or to set up the sub perfectly, if needed). By doing so, you will create the correct crossover point between the sub and your main stereo pair, ensuring that the bass will be clean and booming-free. Furthermore, the dynamic range of the main speakers will increase, and their distortion decrease, because they will no longer struggle to reproduce (in vain) the low frequencies your sub is better qualified to manage. Image and clarity in the mid and high-range will improve too because of the reduced distortion of the loudspeaker. Connecting a sub to the speakers without rolling off the low frequencies in the amplifier (and consequently in the speakers), as anyone unfortunately does, is completely wrong, and it's the reason why the audiophiles think that a sub dirties the sound of a hi-end system! In reality, this is only due to their technical ignorance and that of the hi-end insiders! NOTE: If your speakers are floorstanders and tend to “boom” (this is in the "DNA" of these speakers), even if you don't have a sub, try the roll-off option and you will probably be amazed about the transformation in the bass department and the rest of the audio band too. Please call us for a better explanation of this mighty facility. However, as standard, every sachem v.3 leaves the factory set up to full range (flat response). If you plan to bi-amp your speakers with a second pair of sachem v.3, connect your preamp to the red RCA input of the amps driving the low spectrum, then connect their white socket to the red socket of the monoblocks handling the mid-high. In this configuration, you must roll off the bass response in the monoblocks used for the high frequencies, setting up the highest possible roll-off point (260Hz -3dB).
On the back panel of each monoblock, there are the connection sockets: the red input RCA socket receives the signal from your preamp. The white one is a line output that can be used for feeding the signal to other units, in multi-amplification, or for driving an active subwoofer if you don't want to connect it to the preamp. At this point, I have to introduce you to an uncommon but very useful facility of our amplifier: the ability to select a flat response or, via its passive high-pass filter, a 6dB/oct rolled-off response, with three selectable -3dB points at different frequencies. You must choose one of these roll-off options if you connect a subwoofer (contact us for further explanation or to set up the sub perfectly, if needed). By doing so, you will create the correct crossover point between the sub and your main stereo pair, ensuring that the bass will be clean and booming-free. Furthermore, the dynamic range of the main speakers will increase, and their distortion decrease, because they will no longer struggle to reproduce (in vain) the low frequencies your sub is better qualified to manage. Image and clarity in the mid and high-range will improve too because of the reduced distortion of the loudspeaker. Connecting a sub to the speakers without rolling off the low frequencies in the amplifier (and consequently in the speakers), as anyone unfortunately does, is completely wrong, and it's the reason why the audiophiles think that a sub dirties the sound of a hi-end system! In reality, this is only due to their technical ignorance and that of the hi-end insiders! NOTE: If your speakers are floorstanders and tend to “boom” (this is in the "DNA" of these speakers), even if you don't have a sub, try the roll-off option and you will probably be amazed about the transformation in the bass department and the rest of the audio band too. Please call us for a better explanation of this mighty facility. However, as standard, every sachem v.3 leaves the factory set up to full range (flat response). If you plan to bi-amp your speakers with a second pair of sachem v.3, connect your preamp to the red RCA input of the amps driving the low spectrum, then connect their white socket to the red socket of the monoblocks handling the mid-high. In this configuration, you must roll off the bass response in the monoblocks used for the high frequencies, setting up the highest possible roll-off point (260Hz -3dB).
internal view (from front to back) and the power supply
Now, talking about the speaker cables, you will find a one-metre-long NORDOST 2 FLAT cable in every box, with an end terminated with a NEUTRIK Speakon plug (simply the best, with an electrical current/contact rating of 40A RMS).
We have no relationship with the NORDOST distributor, allowing us to be completely unbiased. Therefore, the only reason we chose this cable is that, in all our trials of speaker cables, it turned out to be superior to all others we tried (including some indecently expensive ones) in terms of clarity, bass control, and speed.
Indeed, there are technical reasons for its excellent performance, which, in my opinion, are due to outstanding electrical parameters: capacitance 23pF/m, inductance 0.55μH/m and the propagation at 90% speed of light!
We believe this cable is the best choice (or at least one of the best choices) to fully transfer sachem's huge potential to your speakers, despite its reasonable price.
To discover the polarity of the accompanying Nordost cable, carefully examine its external white plastic cladding. You will note that the plastic cladding of one wire is completely smooth, while the other one has a line in relief along the middle. The marked wire is the positive, and the smooth one is the negative.
However, you are free to try other brands and types of cable, but whatever cables you choose, keep them as short as possible. To connect a speaker cable to the monoblock, you can either use the professional NEUTRIK Speakon connector, or the binding posts (the easiest solution and equally good).
In connection to the speaker cables, we must inform you that sachem v.3 features NO protection against a short circuit in the speaker cable, which will instantly “kill” the power stage of your amplifier!
Inevitably, protection measures introduce sonic compromises and performance limitations, so we have refused to adopt any, in the reasonable expectation that our customers, who are unlikely to be “hi-fi beginners”, will connect their speakers with the requisite care.
Anyway, before disconnecting or connecting a speaker cable, always be sure that the amplifier has been switched OFF for at least 30 seconds. We also recommend disconnecting the Neutrik Speakon plug before the speaker ends.
Please note that the warranty will NOT cover the cost of addressing any problem caused by a short on the speaker cable.
Darlington devices in the power stage and (in centre) the pure Class A driver stage
Safeguarding sachem v.3 from overheating is simple. Do not place the amplifiers within an unventilated enclosure, such as a closed cabinet or any piece of furniture. The monoblocks must be kept in open air, on a hard surface, not on carpet or any other soft material that might block or restrict the vents underneath. It's also mandatory to keep the units, especially the black version, OUT of direct sunlight.
If these directions are not met, the amplifier won’t run at its optimal temperature, creating the conditions for a possible “thermal runaway”, which could destroy the power stage!
Finally, we hope you now feel prepared to use and care for your new, stunning monoblocks.
We are confident that you will enjoy the improved performance of your system! However, it’s important to realise that a pair of sachem v.3 won’t work miracles. Instead, these amplifiers will ruthlessly expose any weaknesses in your hi-fi chain. Similarly, their full potential may be "obscured" by any other component in the system lacking selectivity, speed, and clarity.
Indeed, a merciless reality of the hi-fi world is that the final sound of a system is mainly conditioned by its worst component, not its best one!
So, until all the components in your system match the calibre of your new v.3 monoblocks, your quest for sonic perfection will remain partially unfulfilled!
close view of the pure Class A driver stage (in centre)
To finish, a note about the name: “sachem” (pronounced sakèm) refers to the general Chief of all the American Indians. The word originates from the Algonquian language of a tribe that lived near Lake Michigan. The Indians also used the epithet “sachem” as an honour for a senior warrior who had distinguished himself with particular merits.
Please do not hesitate to contact us if you need assistance or advice with the installation and use of our products, or if you have any general hi-fi-related curiosities or questions! Many thanks indeed to my very dear friends and highly skilled technicians, Rino Cieri and Allen Gill, who have helped me "more than once" to solve big problems! Also, thanks to Kevin Munt, who machined the cabinets to perfection.
Please do not hesitate to contact us if you need assistance or advice with the installation and use of our products, or if you have any general hi-fi-related curiosities or questions! Many thanks indeed to my very dear friends and highly skilled technicians, Rino Cieri and Allen Gill, who have helped me "more than once" to solve big problems! Also, thanks to Kevin Munt, who machined the cabinets to perfection.
specifications
NOTE: the parameters in red are paramount, but usually omitted in the specs of many amps! Rated continuous power (RMS) 8Ω (20Hz ~ 20kHz) > 90W
Rated continuous power (RMS) 4Ω (20Hz ~ 20kHz) > 165W
Rated non-continuous power 2Ω > 300W
Peak max. transient current on load - see note below (**) > 20A
Input sensitivity ~ 1.3V
Input impedance 13kΩ
Internal impedance < 0.1Ω
Power bandwidth @ -3dB (top-band limited by input passive low-pass filter) 2Hz ~ 240kHz
Audio-band linearity 5 ~ 200kHz (@ rated power) ± 0.1dB
Phase deviation 20Hz ~ 20kHz < 3º
THD @ rated power 8Ω 1kHz < 0.03%
Crossover distortion NO trace
Signal-to-noise ratio (input shorted) NO audible noise Hi-pass filter-slope (see instructions) 6dB/oct @ xxx Hz
Overall dimensions (W-D-H) 300 – 410 – 165 mm Shipping dimensions (W-D-H) 510 - 420 - 290 mm
Shipping weight 13.2 kg
(**) Please note that a current of 20A is equivalent to peaks of 1600W @ 4Ω and 3200W @ 8Ω
Rated continuous power (RMS) 4Ω (20Hz ~ 20kHz) > 165W
Rated non-continuous power 2Ω > 300W
Peak max. transient current on load - see note below (**) > 20A
Input sensitivity ~ 1.3V
Input impedance 13kΩ
Internal impedance < 0.1Ω
Power bandwidth @ -3dB (top-band limited by input passive low-pass filter) 2Hz ~ 240kHz
Audio-band linearity 5 ~ 200kHz (@ rated power) ± 0.1dB
Phase deviation 20Hz ~ 20kHz < 3º
THD @ rated power 8Ω 1kHz < 0.03%
Crossover distortion NO trace
Signal-to-noise ratio (input shorted) NO audible noise Hi-pass filter-slope (see instructions) 6dB/oct @ xxx Hz
Overall dimensions (W-D-H) 300 – 410 – 165 mm Shipping dimensions (W-D-H) 510 - 420 - 290 mm
Shipping weight 13.2 kg
(**) Please note that a current of 20A is equivalent to peaks of 1600W @ 4Ω and 3200W @ 8Ω
sachem v.3 (or v.2) are on display at the following dealers:
Leonard Lucas - Auckland
Signals - Auckland
HiFi Auditions - Hamilton
Tone Electrical - Paraparaumu
(you'll find their contact details on the "partners" page)
PLEASE NOTE: If you do not live in an area covered by one of our local dealers, please contact us. We will create an alternative solution to ensure you can experience and enjoy the sachem "difference".
HiFi Auditions - Hamilton
Tone Electrical - Paraparaumu
(you'll find their contact details on the "partners" page)
PLEASE NOTE: If you do not live in an area covered by one of our local dealers, please contact us. We will create an alternative solution to ensure you can experience and enjoy the sachem "difference".